Process of making electric-lamp filaments.



v UNITED STATES PA ENT oFFroE.

WALTER G. CLARK AND HERSCHEL C. PARKER, OF NEW YORK, N. Y., ASSIGNORS TO PARKER- CLARK ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PROCESS OF MAKING IELIEC'IJRICi-LAMI :FILAMZENTS.

To all whom it may concern:

Be it known that we, WALTER G. CLARK,

' of the city, county, and State of New York,

and HERSCHEL- O. jPARKER, of the city of New York, county of Kings, and State of New York, have invented a new and Improved Process of Makin Electric-Lam Filaments, of which the fol owing is a ful clear, and exact description.

We have demonstrated b many experiments that man processes heretofore tried for coating a ament with silicon have been-unsat sfactory owing to the fact that no means was provided for taking up chlorin or h dro-chloric acid freed by the processes w ere the processes employed a drocarbon and some volatile silicon c orid. Our experiments have demonstrated that it was essential to provide only such hydro-carbons as will break up at the temperature produced, and combine with the chlorin liberated, forming thereby a new a product containing chlorin, hydrogen and carbon, that occasionall this proper combination was found in il uminatmg gas, but

as the composition of illuminating gas varies from time to time, depending on method of .manufacture, temperature con- .ditions, etc., it would be only by accident that the proper combination would be secured, and when secured, the resence of other hydro-carbons which brolie up and deposited carbon at the temperature attained, produced a filament of low resistance and containing but a com aratively small percentage of silicon. e have found that the proper combination is what is known as marsh gas together with sufiicient olefiant as freed immediately re-combined with the follows.

- Si()1 (hydro carbon) OH, SiC 4HCl. In this reaction it was found that the chlorin silicon until the deposit secured was practically carbon, but assuming that all s1 icon was deposited, the resultant product would be S i-C 4HC1, so that as much carbon Specification of Letters Patent. Application filed November 30, 1906. Serial No. 3461835.

Patented Jan. 14, 1908.

would be de osited as silicon, but as the Si was attache by either the C1 or the HCl at this tern erat'ure, only a small amount of- Si was eposited with the C, but with the combination of marsh gas, olefiant gas, and carbon dioxid, together with the volatile silicon compound or silicon tetra-chlorid, We secure the following reaction SiCL, OH, 40, H, 00

- i Si 4 (O,H Cl) a 2((30).

By this reaction it will be noted .that the chlorin is taken care of in the formation of ethyl-chlorid 0,11 1, or C I-Ll ethylenechlorid, and that carbon 'dioxid is reduced to carbon monoxid, thereby taking care of the other atom of carbon. .If We omit the CO we find that We secure a deposit on the filament of silicon and carbon, but with the correct pro ortions of CO, present, the de osit on t e filament is rich in silicon.

uring our early ex eriments Wewe're deceived into thinking t at any hydro-carbon gas would bring about the necessary reaction, y the fact that the illuminating gas we were using at that time happened to contain a smal percentage of the above named gases which brought about the reaction, but by along series of experiments, and by elimination, we have ascertained just what is nec-' essary to bring about the reaction, and present our claim as a method ofsecuring a deposit rich in silicon by-breaking u or disassociating volatile silicon chlori in the presence of a hydro-carbon gas preferably marsh gas containing a sufficient percentage of olefiant gas to take up the hydrochloric acid or chlorin, freed in breaking up the silicon chlorid, thereby forming a com ound of chlorin, hydrogen and carbon, whic 1 may be either ethyl-chlorid or ethylene chlorid, or both, and providing carbon dioxid gas or some other similar agent is used to take up and combine with the carbon freed from the marsh gas at the time of the disassociation of the hydrogen and carbon of that gas, when a deposit very rich in silicon is secured.

Having thus fully described our invention,

we claim as new and desire to secure by Let- 1. The herein described process of making electric light filaments, which consists in heating a filament b passing a current through it, and thereby epositing silicon on the filament from a volatile chlorid, by breaking up the chloridthrough the agency of marsh gas 4. The herein described process of making and a reactive agent, and in the resence of a suitable absorbent for the freed ydrochloric acid or chlorin.

2. The herein described rocess of making filaments for incandescent amps, which consists in passing an electric current through a filament, in an atmos here containing marsh gas, olefiant gas, an a reactive agent containing oxygen, together with a volatile sili-.

con compound.- a

3. The herein described process of making filaments for incandescent electric lamps, which consists in heating a filament by passing an electric current through it in an atmosphere containing marsh gas, olefiant gas,

carbon dioxid, and a substance containing silicon, wherebywe secure the following reaction electric lamp filaments which consists in passbase in a vapor of silicon compound containing chlorin together with a reactive agent, a hydro-carbon and an absorbent to combine ing'a current of electricity through a filament with the'substance freed .by the reduction of the silicon compound.

5. The herein described rocessof making filaments for incandescent amps, which con sists in passing :anelectric current through the filament, thereby heating it, in an atmosphere containing a silicon compound, marsh gas, olefiant gas, and carbon-dioxid.

. WALTER coma K HERSCHEL c. PARKER.

' "Witnesses: WARREN B. HUToHINsoN, FRAN L. STUBBs. 

